The present invention relates to a mixing/charging port for a medical treatment, which is mounted on a medical instrument to make it easy and reliable to mix/charge solutions from the outside of a solution feed passage or, contrarily, to collect the solutions from the inside of the solution feed passage.
In infusing a liquid medicine or transfusing blood into the vessel of a patient, it is often necessary to provide a main solution feed passage with a side-infusing line in order to mix/charge different kinds of liquid medicines or to collect the liquid flowing in the solution feed passage as a sample. Conventionally, in this case, a solution feed passage of an infusion set provided with a rubber mixing/charging port (cock) for piercing by needles is used and solutions are mixed/charged by piercing the mixing/charging port with an injection needle, etc. However, in the conventional method, when piercing the site other than the predetermined piercing site of the mixing/charging port with the needle, the liquid may leak from the site. Another problem is that the injection needle is contaminated due to a working error, etc. In particular, since the mixing/charging port is not designed to hold an injection needle or a syringe at the mixing/charging port, when a liquid medicine continuously is required to be mixed/charged, it is necessary to provide the mixing/charging port with various means for fixing and holding a luer, etc. to be inserted (xe2x80x9can insertion memberxe2x80x9d will be referred to hereinafter). Thus, it was inconvenient to use such a mixing/charging port. For example, it was necessary to wind a syringe needle base and the mixing/charging port together heavily with a tape so as to be fixed to each other. For another example, it was necessary to use a dropping prevention instrument for the piercing needle or the syringe as is disclosed in, for example, JP 5-22187 U. Furthermore, when the side-infusing is carried out, it may be possible to use a three-way valve besides the mixing/charging port. However, when the three-way valve is used, it is necessary to select liquid passages by a cock, thus complicating the operation. In addition, there was a risk of wrongly selecting liquid passages.
Therefore, recently, the mixing/charging port capable of holding an insertion member has been considered. An example includes a mixing/charging port equipped with a valve which opens when a male luer located at the tip of a syringe is inserted into the mixing/charging port to push the valve and which closes by itself when the luer is pulled out from the mixing/charging port.
However, in such a mixing/charging port, it is necessary to hold a luer at the mixing/charging port regardless of whether the state in which the valve is inserted (i.e., valve opens) or the state in which the valve is pulled out (i.e., valve closes). Therefore, there are the following various problems. More specifically, first, it is necessary to deepen a luer receiving part of the mixing/charging port. In such a shape, the liquid leaking from the valve is difficult to be removed, thus easily becoming unsanitary. Furthermore, in the mixing/charging port having such a deep luer receiving part, there is a possibility that the liquid begins to be mixed/charged in a state in which the luer is not sufficiently inserted into the valve. In this case, when a small amount of liquid medicine is mixed/charged, it may be impossible to administer an effective amount of liquid medicine. Secondly, the structure of the valve becomes complicated, which may lead to increasing cost. Furthermore, as the structure of the valve is more complicated, failures are more likely to occur.
On the other hand, in the conventional simple-structured mixing/charging port (for example, a mixing/charging port merely equipped with a disc-like valve made of an elastic member having a slit), it was difficult to insert a luer of a syringe into the mixing/charging port. If possible, it was difficult to hold the syringe reliably at the mixing/charging port. This is because the conventional disc-like valve is formed of a material having a large elasticity and has a simple structure in which the thick main body is merely provided with a slit, so that the valve is subjected to large resistance when the luer is inserted into the valve, and the valve is largely deformed when the valve holds the luer. However, if the thickness of the elastic member is reduced or a material having a small elastic material is used in order to reduce the resistance when the luer is inserted, the backflow prevention effect of the valve is lowered, which may cause liquid leaking.
It is an object of the present invention to avoid the above-mentioned problems and to provide a simple-structured mixing/charging port, in which an insertion member is easily inserted; which is capable of reliably holding/fixing the insertion member at the mixing/charging port and of securing a passage (between the insertion member and the mixing/charging port) when the insertion member is connected to the mixing/charging port; and which is capable of closing the valve when the insertion member is not connected, thereby preventing the liquid from leaking.
In order to attain the above-mentioned objects, a mixing/charging port of the present invention includes a disc-like valve having an insertion hole at the center, a seating for supporting the lower part of the periphery of the valve with the center of the rear surface side of the valve unsupported, a cover for restraining the valve by covering at least the upper part of the periphery of the valve with the center on the front surface side of the valve left uncovered, and an anchor means for anchoring an insertion member to the mixing/charging port by using the edge of the cover which inserts an insertion member into an insertion hole and on which a fitting hole is formed.
According to such a configuration, the length between the insertion member, for example, a luer etc. and the valve can be shortened, and it is possible to easily and reliably disinfect, if necessary, the disc-like valve before and after use. Furthermore, it is advantageous that since the structure is relatively simple, the defective fraction is small and few failures occur.
Furthermore, it is preferable in the mixing/charging port for medical treatment of the present invention that at least two projecting parts are formed on the side surface of the seating and at least two notches engaging the projecting parts are formed on the cover. According to such a configuration, the main body of the mixing/charging port for medical treatment can be fixed reliably to the cover. Moreover, since a solvent such as adhesives etc. is not used when fixing, it is possible to exclude the possibility that the adhesives, etc. may elute into the liquid to be injected or collected.
Furthermore, it is preferable that the mixing/charging port for medical treatment of the present invention further includes a recess part where the valve and the cover can be put in and joined with each other. According to such a configuration, it is possible to anchor the main body of the mixing/charging port reliably to the cover, and also possible to reduce a dead space formed between the bottom surface of the disc-like valve and the passage. The xe2x80x9cdead spacexe2x80x9d herein denotes the space generated between the upper end of the passage and the bottom surface of the disc-like valve.
Furthermore, it is preferable in the mixing/charging port for medical treatment of the present invention that the cover further has a gentle taper on the front surface side. Providing a taper makes it possible to induce the insertion member, for example, a luer, etc. into a fitting hole easily, as well as to wipe out a residual liquid, or to disinfect the mixing/charging port by using an alcohol-impregnated cotton, etc., easily and reliably.
Furthermore, it is desirable in the mixing/charging port for medical treatment of the present invention that a dead space formed between the bottom surface of the valve and the upper end of a passage is 0.05 ml or less. When the dead space is 0.05 ml or more, there is an increased risk that air bubbles are intermixed. Furthermore, the loss of the infused liquid medicine might occur by retention of part of the liquid. In particular, in the mixing/charging port for the liquid infusion, there is a possibility of propagation of bacteria; and in the mixing/charging port for blood transfusion, there is a possibility of clotting of blood.
Furthermore, it is preferable that the mixing/charging port for medical treatment further includes an annular rib formed in an annular form along the edge of the seating on which the hole is provided on the upper part of the seating. According to such a configuration, when the valve is deformed due to the insertion of the insertion member into the mixing/charging port, it is possible to prevent the liquid leakage between the valve and the seating and also to improve the re-closing property of the valve when the insertion member is pulled out and the recovering performance of the valve that caves down. Furthermore, it is desirable that the wall thickness of the edge of the seating on which the hole is provided on the upper part of the seating in the range from 0.3 to 1.0 mm. When the wall thickness is 0.3 mm or less, it is difficult to provide the annular rib; and when it is more than 1.0 mm, the dead space is 0.05 ml or more. Furthermore, it is desirable that the hole provided on the upper part of the seating has a round shape, and the hole diameter is in the range from 5.0 to 8.0 mm. When the diameter is 5.0 mm or less, it is difficult to insert the insertion member; and when it is more than 8.0 mm, the dead space becomes 0.05 ml or more. The most preferable diameter of the hole provided on the upper part of the periphery of the seating is around 6.0 mm.
Furthermore, it is preferable in the mixing/charging port for medical treatment of the present invention that the anchor means is a round fitting hole formed at the center of the cover, and the fitting hole anchors the insertion member by the edge of the cover on which the fitting hole is formed. According to such a configuration, the insertion member easily can be anchored without using an anchor means having a specific mechanism. Furthermore, the insertion member can be anchored penetrating through the disc-like valve. Consequently, it is possible not only to infuse the liquid but also to collect the liquid. Furthermore, it is desirable that the fitting hole has a hole diameter in the range from 3.9 to 4.4 mm and a wall thickness of the part of the cover on which the fitting hole is provided and which is in contact with the insertion member in the range from 0.3 to 1.0 mm. If the ranges do not fall in the above-mentioned ranges, it is difficult to anchor the insertion member. Moreover, the space between the insertion hole or the fitting hole and the valve is increased. Thus, there arise some problems with respect to wiping out of the liquid or sanitary affairs.
Furthermore, it is preferable in the mixing/charging port of the present invention that an annular groove is formed on the surface of the disc-like valve and an annular hook capable of engaging the annular groove is formed on the restrained part of the cover. According to such a configuration, the disc-like valve can be divided into a part compressed and a part stretched by the insertion member, for example, a luer, etc. Thus both the airtightness and operability and re-closing properties can be satisfied at the same time.
Furthermore, it is preferable in the mixing/charging port of the present invention that the outer circumference of the valve has a round shape or an elliptical shape. With such shapes, the insertion member, for example, a luer, etc. easily can be inserted.
Furthermore, it is desirable in the mixing/charging port of the present invention that the insertion hole is a straight slit and the length L0 of the slit is in the range from 3.0 to 4.5 mm. When the length is 3.0 mm or less, it is difficult to insert the insertion member, and when the length is more than 4.5 mm, the airtightness is deteriorated when the insertion member is inserted.
Furthermore, it is desirable that the mixing/charging port of the present invention satisfies: 1.1xe2x89xa6D2/L0xe2x89xa64, wherein D2 is an outer diameter of the valve and L0 is a length of the slit. When the ratio (D2/L0) is less than 1.1, the valve may be deformed or damaged or torn when the insertion member is inserted; and when the ratio is more than 4, the size of the valve is increased. Consequently, the size of the mixing/charging port itself becomes large, and thereby it is difficult to mount the mixing/charging port for medical treatment on a medical instrument.
Furthermore, it is desirable in the mixing/charging port of the present invention that the wall thickness of the valve is in the range from 1.0 to 2.0 mm. It is because the thickness of the valve is preferably made thin in the range in which the liquid does not leak, in order to make it easy to insert the insertion member. Furthermore, it is desirable that the valve is made of an elastic material having a rigidity of 20 to 55 in accordance with JIS-A.
Furthermore, it is desirable in the mixing/charging port of the present invention that the insertion member is fitted penetrating through the valve and the following relation is satisfied: (L1+L2)xe2x89xa6Dxe2x89xa6D max, wherein D max is a maximum insertion depth, D is an insertion depth, L1 is a wall thickness of the valve and L2 is a wall thickness of the part of the cover on which the fitting hole is provided and which is in contact with the insertion member. With such a configuration, it is possible not only to hold the insertion member reliably but also to charge and collect the liquid. It is further desirable that the above-mentioned relationship satisfies: (L1+L2)xe2x89xa6Dxe2x89xa62D max/3.
Furthermore, it is preferable in a mixing/charging port for medical treatment of the present invention that a material of the valve is selected from the group consisting of silicone rubber, natural rubber, synthetic rubber and thermoplastic elastomer. By selecting such a material, it makes it easy to maintain the functions, for example, airtightness, insertion property, re-closing property, and the like.
Furthermore, it is preferable that the mixing/charging port for medical treatment of the present invention further includes a cover holder which has at least two hooks capable of engaging at least two notches provided on the cover and which covers the seating from the lower part, engages the cover covering the seating from the upper part, thereby covering and protecting the seating. It is because there may also be a risk that the projecting part of the mixing/charging port main body is affected and damaged due to the DOP (dioctyl phthalate), etc. from a vinyl chloride tube when the autoclave sterilization is carried out.
Furthermore, it is preferable that the mixing/charging port for medical treatment of the present invention includes at least two projecting parts provided on the side surface of the periphery of the cover and has an anchor means for anchoring the insertion member by using a cylindrical free nut lock having notches engaging the projecting parts, being held with inserted by the insertion member, and inserting the insertion member into the insertion hole while rotating the bottom surface, thereby engaging the notches provided on the bottom surface with the projecting parts of the cover capable of engaging the projecting parts. According to such a configuration, the insertion member can reliably be anchored.